To be absolutely certain, you should:
* Consult your vehicle's repair manual: This is the most reliable source for precise location information.
* Use a repair manual database: Sites like Chilton or AllDataDIY often have diagrams.
* Search online for images: Search "2001 Chevy Silverado 1500 4.3L crankshaft position sensor location" (or the correct engine displacement if it's not the 4.3L) to find images of the sensor's location on similar vehicles.
Remember that working on your vehicle can be dangerous. If you're not comfortable performing this task, it's best to take your vehicle to a qualified mechanic.